Chemistry
by KaosCumberbatch
Summary: Lots of fluff. And my first fic that isn't actually sad.


**Author's Note: **For Sarah, who couldn't handle all of my sad fics. Love you x

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><p>Sherlock had been sitting at his desk all day. He stared at the wall opposite with his hands folded under his chin. John worried about him, but every time he tried to initiate conversation, he received no reply. Not even a nod or a hum. So he went about his day while Sherlock sat, blinking every so often but never shifting his gaze.<p>

The sun was going down even earlier this time of year and the flat was dark. The only light was from the kitchen, seeping into the living room, and an orange glow from the lamp in the corner.

John came out to the kitchen in his thin plaid pajamas, his hair wet from the shower.

"John…" Sherlock said softly, still looking ahead.

John came to the doorway within a few seconds.

Sherlock didn't budge. "John…" he repeated.

"You need something?" John asked quietly.

Sherlock finally looked up. "I need help with an experiment."

"Should I be afraid to ask?"

"Yes," Sherlock said simply as he stood up and moved the little wooden chair to the center of the room. He sat down again and held out his arms. "Come here."

"Ah, no," John said as he started to turn around.

"Please, John," Sherlock said, making him stop and turn around. "It's for science."

John sighed and walked over to him, his hands on his hips.

"Sit in my lap."

"What kind of experiment is this, exactly?"

"Please." Sherlock looked up at him. John could never resist those bright blue eyes and Sherlock knew it.

John reluctantly put his legs on either side of Sherlock's thighs and sat down slowly, facing him. Sherlock took his hands and put them on his shoulders before holding onto his hips.

Sherlock paused for a minute, staring at his hands and trying to remember the feel of John's pulse.

_Only slightly elevated._

He looked up into John's dark blue eyes. "Do you feel anything?"

"I'm feeling a bit strange, to be quite honest."

"Seriously."

"I don't feel anything in particular. Why?"

Sherlock stared at him a while longer. He made a point to glance at John's lips and wet his own.

He could see a faint blush creeping up John's cheeks and moved his thumbs in small circles on his hips. He gently pulled him closer, not being too obvious about it.

"What happens if you mix hydrochloric acid and sodium oxide?" Sherlock asked in a slightly husky voice, testing John's focus.

"Jesus, I don't know," he said with a slight laugh.

"Well, think about it. It's simple chemistry."

"Sherlock, I didn't study chemistry."

"It's primary school stuff. You would get sodium chloride and hydrogen oxide."

"Okay..? So… Water? And salt?"

Sherlock nods and looks down. He couldn't help but notice John's muscles under his shirt.

_He's been working out again._

He felt his heart beat faster and he bit his lip.

"The first two are compounds that are toxic to the body but the second..." He looked up again and trailed off, lost in John's eyes. He cleared his throat and finished weakly. "...the second two you can't live without."

_Pupils dilating._

John unconsciously played with a curl in Sherlock's hair and laughed softly.

"You're an idiot."

Sherlock smirked. "At least I know the first thing about chemistry."

"At least I know that the earth goes around the sun."

Sherlock rolled his eyes and was silent for a moment. They just stared at each other for a long time.

"One of my favorite elements is gallium. Atomic number 31. It melts right in the palm of your-"

"Would you just shut up?" John muttered as he put his hands on the back of Sherlock's neck, pulling him closer. He tilted his head slightly and pressed their lips together.

Sherlock gasped softly and eventually his eyes shut and he fell into the kiss. He moved his lips against John's gently as his heart pounded against his chest.

John pulled away and rested their foreheads together. His breaths were quick and shallow, his heart racing just as fast as Sherlock's.

"Why did you do that?" Sherlock mumbled as his eyes fluttered open.

"Should I not have?"

"I-I don't know..."

"I did it because you don't know when to stop talking and get to the point."

"What point?"

"You're talking too much again…" John whispered, a smile tugging at the corners of his mouth.

"Whoopsies," Sherlock replied with a slight smirk.

John laughed and kissed him again, his lips slightly parted.

"I love you, Sherlock… Even if you _are_ an idiot."


End file.
